Russ Doerner - Controlled Fusion Atomic Data Center

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If alloy formation (carbide or beryllide) is responsible for Be layers, then subsequent Be deposition should be quickly re-eroded. Be alloy layers should be thin. C sample, 175°C, f Be ~0.15% W sample (AES data) f Be = 0.1%, 5000 sec., T W = 300°C 100 90 Composition (at. %) 80 70 60 50 40 30 20 10 0 Be (at %) O (at %) W (at %) 0 5 10 15 20 Sputtering Time (min) 0 10 20 30 40 Estimated Thickness (nm) 50 60 UCSD University of California San Diego R. <strong>Doerner</strong>, March 22, 2005 PSIF workshop, ORNL
The dynamic behavior of the Be layer may help decipher the mechanism responsible for surface layer formation. 1.6 • At PISCES-B conditions: f ~ 0.001 Be Γ = 3e18 cm -2 s -1 pl Γ = 3e15 Be/cm 2 s Be or 1 Be monolayer/sec CD/Dg 1.4 1.2 1.0 0.8 0.6 0.4 0.2 0 50 100 150 200 Distance from Target [mm] Discharge time [s] 1940 2670 3500 4100 7050 For 50 eV Be on C the stopping distance is only ~0.5nm, or ~2-3 monolayers Erosion suppression (i.e. CD band decrease) takes much longer Upstream Be conc. (%) 1 0.1 UCSD University of California San Diego R. <strong>Doerner</strong>, March 22, 2005 PSIF workshop, ORNL 0.01 10 1 10 2 10 3 10 4 CD Band strength e-folding time (s)
Page 1 and 2: Erosion Behavior of Carbon and Tung
Page 3 and 4: PISCES-B, and Its Associated Surfac
Page 5 and 6: PISCES-B linear plasma device simul
Page 7 and 8: PISCES-B operation above 6 eV T e p
Page 9 and 10: A small beryllium impurity concentr
Page 11 and 12: Be layer formation effectively elim
Page 13 and 14: Do we understand why these Be layer
Page 15 and 16: WPM samples show collection of bery
Page 17 and 18: Be impurities from the ITER first w
Page 19: What will be the result of Be layer
Page 23: Be impurities may dominate PMI (spe

Russ Doerner - Controlled Fusion Atomic Data Center

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